Lot's of good intel here - thanks. I'm laying the groundwork now and don't anticipate actually buying anything until later. I'm a data guy (which doesn't mean that I'm trying to beat the system) so I've got Yapta set up collecting information and sending me data regularly. At some point the prices on the flights I am tracking are going to start fluctuating, either through the normal algorithms of supply and demand or through airline sales and special offers. At some point I'm going to buy - the data that you are providing will help me to judge where that price point is, so thanks.
Here are my best and worst experience buying flights:
Best: Year 2001 Spring Break - Direct, Round Trip flight on Northwest air from Detroit to Rome for $228. I'm not making this up - it was an introductory rate for the direct route. The plane was full of University of Michigan students.
Worst: Got a good price on a direct Boston to Milan flight through AirOne. When not enough seats were filled, they cancelled the flight and turned it into a boston to Chicago to Milan flight, with a 5 hour layover in Chicago. I refunded by tickets but since I paid in Euros through the AirOne website, I ended up losing approximately $200 just on exchange rate fluctuations over the 6 months between when I bought and when I got the refund. Tack that onto the $200 extra per flight I paid to get a replacement flight!